Luke's carb problems

[rhughes@domain.elided]

Luke,

I've been following the thread concerning your backfiring/stalling scout.
Some very good mechanical minds are throwing in their two cents, so I
figured I'd bring down the average level of advice:

First, hook your vacuum advance back up.  It's hard enough to troubleshoot
a carb without adding the variable of advance.  I think you should do all
you can to make sure the carb is okay before worrying about ignition.

Your symptoms make it sound as if you are getting a really lean mixture
when you open up the throttle quickly.  The accelerator pump was put into
carbs to counteract that very problem.  Whenever you depress the
accelerator, the pump squirts extra fuel into the barrels to balance all
the extra air.

Quick check of the accelerator pump:  With the engine OFF, look down the
barrel of the carb while someone steps on the accelerator.  You should see
two healthy squirts of fuel going down into the barrels.  If you don't,
I'll give you 40 to 1 odds that's your problem.  A carb rebuild (really not
that hard) will fix it right up.

I know you're getting a lot of different advice, but this is a very quick
check.  Keep in mind, if the accelerator pump appears to be working, you
still might have carb problems.  Also, someone suggested that the power
valve might be blown -- I think they actually meant the accelerator pump.
The power valve is a different circuit; it kicks in when the engine is
under heavy load (freeway, uphill), and if it were blown, you'd probably
have a rich mixture.

Keep posting your progress.  We'll get that scout up and running
eventually!

Rob

p.s.  Where are you located?  I don't want to speak for anyone else, but if
you're close enough to me (SLC) I'd be happy to stop by and lend a hand.